High School Mathematics1.8 Solving an Equation by Guess Method

To find the solution of an equation, you may try all the values from the domain of a variable one at a time. However, it would be time consuming. Instead, you can guess the value of the variable for which the equation will be satisfied, i.e., LHS and RHS become identical.

Example: Solve 2x+4 = 62, where x is an integer.Solution:
The domain of the variable x is {1, 2, ...}, i.e., all integers. To solve the above equation, the trial and error approach is to go through all the values from the domain of the variable, substituting one at a time and checking to see if LHS = RHS.

By observing the equation, you could see that the equation may be satisfied for a value of x around 30. Therefore, you may try x=29, 30, or 31. By trying these guessed values, you can verify that the root of the above equation is 29.